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[Solid-phase extraction coupled with high performance liquid chromatography-triple quadrupole mass spectrometry for simultaneous determination of seven coumarins in water samples from drinking water treatment plants]

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Se pu = Chinese journal of chromatography 2025年第1期43卷 78-86页

作者： Wen-Mei Jiao Jing-Ming Yang Ce Xu fu-kang Gao Lu-Yao Shen Yu-Bo Yuan Zhi-Fen Guo Guang Huang School of Life Sciences and Chemical Engineering Jiangsu Second Normal University Nanjing 211200 China. School of Stomatology Nanjing Medical University Nanjing 210029 China. School of Public Health Nanjing Medical University Nanjing 211166 China. Key Laboratory of Modern Toxicology Ministry of Education School of Public Health Nanjing Medical University Nanjing 211166 China.

Chlorinated coumarins, which are as cytotoxic as highly toxic halobenzoquinones toward CHO-K1 cells, have recently been identified as disinfection byproducts in drinking water disinfection processes. Therefore, detecting coumarins in water samples collected at various stages from drinking water treatment plants helps assess the formation of chlorinated coumarins in drinking water. Hence, a simple, rapid, accurate, and sensitive method for quantifying coumarins in water samples is required. In this study, a method was developed based on solid-phase extraction coupled with high performance liquid chromatography-triple-quadrupole mass spectrometry for analyzing seven coumarins in water samples from drinking water treatment plants, including 6,7-dihydroxycoumarin, 7-hydroxycoumarin, 6-hydroxy-4-methylcoumarin, 8-chloro-7-hydroxycoumarin, coumarin, 7-chloro-6-hydroxy-4-methylcoumarin, and 3,8-dichloro-7-hydroxycoumarin. Sample pretreatment involved solid-phase extraction using HLB columns, followed by elution with water and methanol, each containing 0.25% formic acid. The extracted solution was separated via gradient elution using a Phenomenex Luna C18 column (100 mm×2.0 mm, 3 mm) with 0.1% formic acid aqueous solution and methanol as the mobile phases, with analytes detected by triple-quadrupole mass spectrometry equipped with electrospray ionization source in multiple reaction monitoring mode. The matrix effect, precision, and accuracy of the developed method were investigated using raw and treated water as matrices. Matrix effects of 0.84-1.12 were recorded for the detection of 6,7-dihydroxycoumarin, 7-hydroxycoumarin, 6-hydroxy-4-methylcoumarin, and coumarin in raw water, while values of 0.67-0.70 were recorded for 8-chloro-7-hydroxycoumarin, 7-chloro-6-hydroxy-4-methylcoumarin, and 3,8-dichloro-7-hydroxycoumarin in finished water. The three chlorinated coumarins exhibited matrix effects above 0.80 after the finished water matrix had been diluted four times. These re

关键词： coumarins disinfection byproducts drinking water high performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) solid-phase extraction (SPE)

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Tautomerizations and intramolecular hydrogen bondings of the chiral α-nitroester, α-nitrosoester and α-ketoester

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Chinese Science Bulletin 1998年第18期43卷 1531-1536页

作者： fu’an kang Chenglie Yin Department of Chemistry Beijing Normal University Beijing China

Interesting and diverse tautomerizations and intramolecular hydrogen bondings of the chiral α-nitroester, α-nitrosoester and α-ketoester are described and rationally interpreted.

关键词： tautomerization intramolecular hydrogen bonding α-ketoester γ-butyrolactone.

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Bayesian Estimation and Model Selection for the Spatiotemporal Autoregressive Model with Autoregressive Conditional Heteroscedasticity Errors

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Acta Mathematicae Applicatae Sinica 2023年第4期39卷 972-989页

作者： Bing SU fu-kang ZHU Ju HUANG Department of Statistics&Actuarial Science University of Hong KongHong Kong 999077China School of Mathematics Jilin UniversityChangchun 130012China National Energy Administration Information Center Beijing 100045China

The spatial and spatiotemporal autoregressive conditional heteroscedasticity(STARCH) models receive increasing attention. In this paper, we introduce a spatiotemporal autoregressive(STAR) model with STARCH errors, which can capture the spatiotemporal dependence in mean and variance simultaneously. The Bayesian estimation and model selection are considered for our model. By Monte Carlo simulations, it is shown that the Bayesian estimator performs better than the corresponding maximum-likelihood estimator, and the Bayesian model selection can select out the true model in most times. Finally, two empirical examples are given to illustrate the superiority of our models in fitting those data.

关键词： autoregressive conditional heteroscedasticity model Bayesian estimation model selection spatial ARCH model spatial panel model spatiotemporal model

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An automatic docking method for large-scale sections based on real-time pose measuring and assembly deviation control

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Optoelectronics Letters 2023年第11期19卷 686-692页

作者： QIAO Zhifeng fu kang LIU Zhenzhong Tianjin Key Laboratory for Advanced Mechatronic System Design and Intelligent Control School of Mechanical EngineeringTianjin University of TechnologyTianjin300384China National Demonstration Center for Experimental Mechanical and Electrical Engineering Education Tianjin University of TechnologyTianjin300384China

Aiming at the problem of poor accuracy consistency of large sections’docking assembly,an automatic docking method using multiple laser trackers to measure the position and posture of the docking sections in real time was *** the solution of the pose of the docking section,real-time pose measurement of the docking section was realized by establishing a global coordinate system and a coordinate fusion method of three or more laser *** the automatic control of the docking process,the real-time communication protocol and the circular negative feedback control strategy of measurement-adjustment-re-measurement are adopted,and the fully-automated docking of large sections is ***,an experimental verification system was set up,and the docking of the large-scale section reduction models was realized under the requirements of docking accuracy,and the effectiveness of the automatic docking scheme was successfully verified.

关键词： coordinate deviation system

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Highly enantioselective construction of CF_(3) -bearing all-carbon quaternary stereocenters: Chiral spiro-fused bisoxazoline ligands with 1,1'-binaphthyl sidearm for asymmetric Michael-type Friedel-Crafts reaction

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Chinese Chemical Letters 2022年第5期33卷 2415-2419页

作者： Robert Li-Yuan Bao Lei Shi kang fu School of Science Harbin Institute of TechnologyShenzhen 518055China State Key Laboratory of Elemento-Organic Chemistry Nankai UniversityTianjin 300071China Guangdong Provincial Key Laboratory of Catalysis Southern University of Science and TechnologyShenzhen 518055China School of Chemistry and Chemical Engineering Harbin Institute of TechnologyHarbin 150001China

A novel class of chiral spiro-fused bisoxazoline ligands possessing a deep chiral pocket was *** developed ligands have been employed in the nickel-catalyzed highly enantioselective Michael-type Friedel-Crafts reaction, affording the products bearing a trifluoromethylated all-carbon quaternary stereocenter with moderate to excellent yields(up to 99%) and good to excellent enantioselectivies(up to> 99.9% ee). Moreover, a proposed model of chiral pocket revealed that the attack of indole from the Re-face of β-CF_(3)-β-disubstituted nitroalkene was favorable.

关键词： Chiral bisoxazoline ligand Chiral pocket Chiral spiro ligand Friedel-Crafts reaction Trifluoromethylated all-carbon quaternary stereocenter

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Traditional Chinese medicine kang Xian fu Fang Ⅰ is effective for prophylaxis and treatment of alcoholic liver disease in rats

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Hepatobiliary & Pancreatic Diseases International 2007年第2期6卷 182-187页

作者： Xiao-Hui Lv, Li-Ping Zhou, Dong-Ping Liu, Ying Wang, Bing-Yuan Wang, Bao-Yu fu, Min Song and Chun-Rong Liu Department of Gastroenterology , Department of Laboratory Diagnosis , and Department of Pathology , First Affiliated Hospital, China Medical University, Shenyang 110001, China Department of Gastroenterology Lv XH Liu DP Wang Y Wang BY Fu BY and Liu CR Department of Laboratory Diagnosis Zhou LR and Department of Pathology Song M First Afifliated Hospital China Medical University Shenyang 110001 China

BACKGROUND: Reversal of liver fibrosis is one of the key steps in the prevention and treatment of alcoholic liver disease (ALD), but the mechanism is unknown. This study was to investigate the effects of the Chinese medicine kang Xian fu Fang Ⅰ (KXⅠ) on prophylaxis and treatment of ALD in rats and its possible mechanism of action. METHODS: Eighty male Wistar rats were randomly divided into four groups: normal control; ALD model; treatment of ALD with KXⅠ; and prophylaxis of ALD by KXⅠ. At the end of 4, 8, 12 and 16 weeks, five rats from each group were anesthetized and their livers were removed for pathological studies using hematoxylin-eosin and Masson stain, immunohistochemical studies, and flow cytometry for matrix metalloproteinase-2 (MMP-2) and matrix metalloproteinase-9 (MMP-9). Blood samples were taken for hyaluronic acid (HA) assay. RESULTS: Serum HA level and liver collagen content were lower in the groups given KXⅠ for prophylaxis and treatment than in ALD model group (P<0.05). The levels of MMP-2 and MMP-9 were also decreased in the prophylaxis and treatment groups (P<0.05). Immunohistochemistry showed immunoreactive MMP-2 in endothelial cells of the hepatic artery and portal vein, sinusoidal endothelial cells, and sinusoidal cells. Immunoreactive MMP-9 occurred in the hepatic cells around the veins and sinusoidal cells. CONCLUSIONS: KXⅠ can effectively inhibit or reverse the course of ALD. This may be attributable to its capacity to inhibit the expression of MMP-2 and MMP-9.

关键词： matrix metalloproteinase alcoholic liver disease flow cytometry immunohistochemistry

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New Sixth-Order Compact Schemes for Poisson/Helmholtz Equations

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Numerical Mathematics(Theory,Methods and Applications) 2023年第2期16卷 393-409页

作者： Kejia Pan kang fu Jin Li Hongling Hu Zhilin Li School of Mathematics and Statistics HNP-LAMACentral South UniversityChangsha 410083China MOE-LCSM School of Mathematics and StatisticsHunan Normal UniversityChangsha 410081China CRSC&Department of Mathematics North Carolina State UniversityRaleighNC 27695-8205USA

Some new sixth-order compact finite difference schemes for Poisson/Helmholtz equations on rectangular domains in both two-and three-dimensions are developed and *** from a few sixth-order compact finite difference schemes in the literature,the finite difference and weight coefficients of the new methods have analytic simple *** of the new ideas is to use a weighted combination of the source term at staggered grid points which is important for grid points near the boundary and avoids partial derivatives of the source ***,the new compact schemes are exact for 2D and 3D Poisson equations if the solution is a polynomial less than or equal to *** coefficient matrices of the new schemes are M-matrices for Helmholtz equations with wave number K≤0,which guarantee the discrete maximum principle and lead to the convergence of the new sixth-order compact *** examples in both 2D and 3D are presented to verify the effectiveness of the proposed schemes.

关键词： Poisson equation Helmholtz equation sixth-order compact scheme maximum principle staggered grid.

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Notes and correspondence on ensemble-based three-dimensional variational filters

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Journal of Zhejiang University-Science C(Computers and Electronics) 2013年第8期14卷 634-641页

作者： Hong-ze LENG Jun-qiang SONG fu-kang YIN Xiao-qun CAO College of Computer National University of Defense Technology

Several ensemble-based three-dimensional variational (3D-Var) filters are compared. These schemes replace the static background error covariance of the traditional 3D-Var with the ensemble forecast error covariance, but generate analysis ensemble anomalies (perturbations) in different ways. However, it is demonstrated in this paper that they are all theoretically equivalent to the ensemble transformation Kalman filter (ETKF). furthermore, a new method named EnPSAS is presented. The analysis shows that EnPSAS has a small condition number and can apply covariance localization more easily than other ensemble-based 3D-Var methods.

关键词： 3D-Var Ensemble Kalman filter (EnKF) Ensemble transformation Kalman filter (ETKF) Physical space analysis system (PSAS) Ensemble data assimilation

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Conformational Analysis of γ-Butyrolactones by Nuclear Magnetic Resonance Spectroscopy

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Chinese Chemical Letters 1997年第10期8卷 885-888页

作者： fu An kang and Cheng Lie YIN (Department of Chemistry Beijing Normal University , Beijing 100875) BEIJING NORMAL UNIV DEPT CHEMBEIJING 100875PEOPLES R CHINA

A series of trans-4, 5-disubstituted -γ-butyrolactones are found to assume two different envelope conformations by means of nuclear magnetic resonance spectroscopy.

关键词： Conformational Analysis of Butyrolactones by Nuclear Magnetic Resonance Spectroscopy

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Asymmetric 1,3-Dipolar Cycloaddition of the Chiral Nitronic Esters with Acrylate

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Chinese Chemical Letters 1997年第12期8卷 0-0页

作者： fu An kang and Cheng Lie Ym(Department of Chemiscy Beijtw Normal Unthersho Beijing 100875) Department of Chemistry Beijing Normal University Beijing 100875 China

Asymmetric 1,3-dipolar cycloaddihon of the chiral nitronic esters with acrylate giving the enantiomerically pure novel chiral bisheterocyclic compounds is describcd

关键词： Asymmetric 1 3-Dipolar Cycloaddition of the Chiral Nitronic Esters with Acrylate

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